Clamping directly to freshly painted or ultra thin walled frame tubing can cause inadvertent damage. The new ISC 4 securely holds most bikes without clamping on any frame tube. To use, simply insert the ISC 4 into the frames seat tube, tighten the knob, and clamp into any Park Tool Repair Stand. The ISC 4s hex shaped shaft resists twisting while clamped in the stand. Works with a huge range of seat tube sizesanything with an inside diameter of 24mm to 32mm.